Evolution / Genetics

Pittsburgh tech freeze an Italian city in time by creating a 3-D model

In the image of Volterra, Italy’s original Etruscan arch, every detail of the facade was clear — the stone arch and three heads chiseled into the rock that watched from overhead.

Footage
of 3-D models of the historic site, created from drone photography in
Autodesk ReCap [Credit: Autodesk, Inc. and Volterra-Detroit Foundation]

But this wasn’t a photo of Porta all'Arco, the highlight of the medieval walled city’s gateway. It was an expertly produced 3D model of the Tuscan town’s architectural darling from the 4th century B.C., known as one of the last standing Etruscan arches in the world.

The photo and the model look strikingly alike, which is exactly the purpose of the expedition.

Technology and historical preservation collided as part of the International Reality Capture Workshop — a collaboration between Carnegie-based software company Case Technologies, the Volterra-Detroit Foundation, East Liberty-based Autodesk and the municipality of Volterra itself to document the town’s remaining architecture, digitally.

The first moment he saw the arch, Touf Hassoun, president and CEO of Case Technologies, said he felt transported back in time.

“That was the first time I’ve ever seen such an arch, it’s one of only two of its kind left in the world,” he said. “It felt like you were living 2,000 years in the past.”

To recreate this feeling for tourists, architects, academics and the 7,000 or so inhabitants of the town, the reality capture team traveled to Volterra for two weeks in October 2016 to collect the data needed to create a model.

Accuracy is prime, said Mark Dietrick, an architect as well as director of services at Case Technologies. “We’re trying to use technology to document what already exists.”

Footage
of 3-D models of the historic site, created from drone photography in
Autodesk ReCap [Credit: Autodesk, Inc. and Volterra-Detroit Foundation]

Case Technologies, which offers computer-aided design software developed by Autodesk Inc., has worked since 1989 to provide AutoCAD solutions to various vendors. Since CAD workstations aid in the creation, modification and analysis of a design, it was a natural leap for Case Technologies to move into the International Reality Capture Workshop.

Mr. Hassoun said a future business model could involve cities employing Case Technologies to build 3D models for architectural reference, for tourism or for maintenance.

Since Case Technologies is an Autodesk authorized reseller, it can already sell and integrate Autodesk products. That means both Pittsburgh-based companies have stake in a future business venture, tapping on one another’s expertise and products.

For now, though, they’re not charging for the modeling service, but providing it “for the preservation of architecture,” he said.

In 2014, part of Volterra’s medieval wall collapsed, illustrating the vulnerability of the ancient site.

The town hoped to preserve the Etruscan architecture to apply for the United Nations Educational, Scientific and Cultural Organization World Heritage site classification. A detailed 3D product could explain, without words, why the classification is justified, Mr. Hassoun said.

The cameras attached to the drones took images every four seconds and could fly for 20 minutes before the batteries died. Mr. Dietrick estimated that every time the team flew a drone, they captured about 300 images.

Using a process that stitches together photos into a continuous image, the team logged the historical structures, visually.

Then, terrestrial laser scanners — the light detection and ranging software, or lidar, that is also used in autonomous vehicles — helped to create a point cloud through continuous scans.

“The lidar is going to be the most accurate,” Mr. Dietrick said. “It sits on a tripod 320 degrees vertically and 360 degrees around” to allow the laser to capture every point in a globular manner.

To capture Volterra’s Roman Theatre, it took 120 scans, many of which had to be redone if anything blocked the laser, an inconvenience Mr. Dietrick called “shadows.”

The points, however detailed, are still colorless. To create a more holistic model, pixels from the panoramic photos are fused together.

That data fusion, which relied on cloud-based Autodesk software, required so much bandwidth that the team had to complete uploads at night, when the rest of the town was sleeping.

In the end, the 3D model looks just like the photo of the real thing. “It’s very difficult to differentiate between the two, which points to the accuracy,” said Mr. Hassoun.

A
point could computer generated image of the Roman theatre in Volterra,
Italy, which looks strikingly similar to an actual photo [Credit: Case
Technologies]

Upon returning to the Italian town on June 28, the team presented their final product to Volterra’s Mayor Marco Buselli and his staff.

“The [town] loved what we’re doing and they wanted to continue working with us,” Mr. Dietrick said.

The presentation included virtual reality video that, when experienced through goggles, mimics the experience of walking through Volterra’s historical sites.

In the future, the town might use the goggles outside for tourist attractions, to create an augmented reality experience wherein footage of how the site may once have looked thousands of years ago can be compared to the modern-day ruins.

The technology can also be employed as a preventative measure against natural disasters. “God forbid there is an earthquake, a terror attack or a landslide,” Mr. Hassoun said. “We can capture it to help the city rebuild faithfully.”

Mr. Dietrick noted the model could also be used for historic adaptions or to retrofit projects as time decays the architecture.

“We can see what is deteriorating or shifting if you scan every few years,” he said.

“But it doesn’t have to be medieval. This technique can be used in any city to protect its architecture.”

Mr. Hassoun noted that pilot tests, such as the one in Volterra, could lead to a successful business — especially if the model has been shown to improve historical restoration, applications to historical or global societies or even increase tourism.

These are tangible efforts that may mean profitable ventures in the future, he said.

“After several successful workshops, we want to do this for various governments to protect important sites,” he said. “We want to become the experts in this field and become top-notch scientists.”